Ulamog & Fblthp Unexpected Duo

Ward {4}, Annihilator 4, Indestructible.
You may look at the top card of opponents' libraries at
any time.
Whenever this creature attacks, exile the top five cards of defending player's library. You may play lands and cast
spells from among cards exiled this way for as long as
they remain exiled. you may spend mana as though it
were mana of any color to cast spells this way.
Whenever this creature is put into your graveyard from
the battlefield, shuffle your graveyard into your library.